against the grain

Paper which has been folded at right angles to the
direction in which the fibers tend to lie, i.e.,
the MACHINE
DIRECTION . A well-produced book always has
the grain or machine direction running from head
to tail so that the back or binding fold of the
paper is not against the grain. Correct grain
direction means that the leaves of the book will
be more inclined to lie flat when the book is
open. The term applies specifically to
machine-made paper, asHANDMADE PAPER has no
definite grain direction.